1. Field of the Invention
This invention relates to downhole well tools and, in particular, to an overshot tubing retriever.
2. Description of the Prior Art
For any of a variety of reasons, tubular members may become lodged or otherwise hung up within a well bore. When this occurs, it is necessary that the tubular member, commonly called the "fish", be expeditiously retrieved from the bore so that further drilling operations may continue.
The tubular member may be retrieved by the insertion of a fishing tool adapted to engage the tubular member from the interior surface thereof so that the member may be retracted from the bore. Alternatively, apparatus known in the art as an overshot may be utilized which, when lowered into the bore, receives the tubular member therewithin and operates on that member from the exterior surface thereof so as to either sever a predetermined portion of the tubular member or otherwise engage the same to permit the withdrawal thereof.
There are devices in the art known as "junk catchers" or "junk baskets" which utilize a pivoting arrangement of finger members or the like disposed on the interior of an overshot to retrieve core samples, drill bits, and the like. However, such devices, when the fingers are perpendicular to the interior surface of the overshot, completely close the cross sectional area thereof, and are not adaptable to retrieve axially extending tubular members.